Today we explore the human body. Specifically, we take a tour of our largest organ: the skin. Skin is not only large; it is important.

One of its jobs is to protect us. It keeps bad things out. But sometimes it fails. Extremely small bugs, called mites, can get under our skin. And when they do, they cause itching and great discomfort.

So, to get under someone's skin means to annoy them or, better still, to bug them. Get it? Mites are small bugs.

Okay, moving on! That's just one definition of the expression “to get under someone's skin.”

It can also mean that someone is very attractive to you. You can't stop thinking about them. You might even be obsessing about them. Cole Porter used the expression this way in his 1936 love song “I've Got You Under My Skin."

I've got you under my skin.
I've got you deep in the heart of me.

Let's hear the same expression used different ways in two short examples.
A: Can you stop popping your gum? I need to study and it's really annoying.
B: Sure.
A: And can you stop whistling, please?!
B: Anything you say.

That was an example of the annoying situation. Now, let's move to obsession!
A: Hey, have you seen Jacob recently?
B: He met this new woman at a party last month. So, no. I haven't seen him.
A: What do you mean?

B: I mean, he's fallen hard for her. He's either with her or at home waiting for her call.
A: Wow, she's really gotten under his skin.
B: That's one way to put it. I just tell him that he's obsessed with her.

Now, let's get back to skin as a protector. Our skin fits tightly on our bodies. It holds in important things while keeping out harmful things. So, we can use a “skin” expression to describe very tight clothing. We can say that the outfit fits like a second skin.

There are many ways to describe people using the word "skin." If someone is thick-skinned they are not easily hurt emotionally. You can criticize them or be unkind to them and it simply rolls off their back.

Thin-skinned people, however, are easily hurt by criticism, even if it is not too severe. You have to be careful what you say to thin-skinned people so as not to hurt their feelings.

If someone is suddenly very scared, you can say they nearly jumped out of their skin! For example, one day I saw my friend Sierra waiting at a bus stop. She was wearing headphones and did not hear me come up behind her. So, when I touched her shoulder, she nearly jumped out of her skin!

If someone is too thin and looks sickly, you can say they are all skin and bones. It appears they have no meat or muscle on their bodies. For example, let’s imagine that two hikers get lost in the woods. When rescuers find them weeks later, they are all skin and bones.

Now, let's say you meet someone who is very strange and creepy. You get a very bad feeling around them. You can say they make your skin crawl.

But if you meet someone who is very confident, you can say they are comfortable in their own skin. These people have accepted themselves as is -- flaws and all!

And if you meet someone who is beautiful on the outside but is not very nice on the inside, you can say, “Well, beauty is only skin deep."